Proposal for the Development of an Economically Viable Lunar Base

PROPOSAL FOR THE DEVELOPMENT OF AN ECONOMICALLY VIABLE LUNAR BASE

An Interactive Qualifying Project Proposal submitted to the faculty of Worcester Polytechnic Institute as a requirement for a Degree of Bachelor of Science

Submitted by:

Scott Gary

Oscar Nemeth

Daniel White

Cody Wojcik

Project Advisor:

Roberto Pietroforte

April 28, 2008

Abstract

The prospect of an economically viable lunar base holds promise for the future of mankind. We have yet to inhabit another celestial body, and have only recently set foot on our closest neighbor- the mo.The purpose of this paper is to show that a base on the moon would not only advance man kind. , A lunar base that is self-sufficient could bring unprecedented scientific developments for mankind.buit would also provide a promising resource by which future missions into space would be cheaper from raw materials gathered and sent from the moon. Being ableLunar regolith is quite rich in many metals , such asincluding iron, titanium, magnsesiummagnesium, and aluminum. These metals can be used to further expand a lunar base, as well as be used for construction. . Another promising commodity that is found in much greater concentrations on the moon is the Helium-3 found on the outer layer of regolith which coats the entire surface of the moon.Helium-3, found in the regolith that covers the moon, is present in much greater quantities than on Earth Helium-3 shows promise for future reactors because the reaction needed to product energy will be able to be contained within an electrostatic shield whereas the tritium reactors using hydrogen-3 cannot be properly contained with such a shield.. Helium-3 can power fusion reactors, and its rarity has been a major impediment to fusion reactor development on earth. A lunar mining colony will require an initial investment, but it will more than pay for itself when it is sufficiently developed. An economically viable lunar base promises to extend mankind’s reach well into the solar system.

Table of Contents

Abstract

Table of Figures

Table of Tables

1: INTRODUCTION

1.1: Exploitation of Lunar Resources

1.2: Science

1.3: Tourism

2: OVERVIEW OF THE DEVELOPMENT OF A LUNAR BASE

2.2: Functional Requirements

2.3: Base Development

2.4: Phase I

2.5: Phase II

2.6: Phase III

2.7: Phase IV

2.8: Phase V

2.9: Phase VI

3: DETAILS OF PHASES 1, 2, AND 3

3.1: Unmanned Assembly

3.1.1: Site Selection

3.1.2: Materials and Equipment

3.2: Arrival of Crew

3.2.1: NASA’s Lunar Lander

3.2.2: Solar Power Plant

3.2.3: Additional Materials

3.3: Base Becomes Sustainable

3.3.1: Mining Facility

3.3.2 Agriculture

3.3.3: Logistics Network

3.3.4: Additional Crew Arrive

4: HABITAT DESIGN

4.1: Possible Construction Methods and Layouts

4.2: Proposed Design

4.3: Habitat Materials and Construction Considerations

4.4: Habitat Module

4.5: Airlock Connectors

4.6: Assembly of Modules

4.7: In-Situ Passive Bulk Shielding

5: POWER

5.1: Introduction

5.2: Solar Voltaic Energy

5.3: Solar Dynamic Energy

5.4: Nuclear Energy

5.5: Energy Storage

5.5.1: Capacitors

5.5.2: Gravitation Field Storage

5.5.3: Flywheel

5.5.4: Batteries

5.5.6: Regenerative Fuel Cell

5.6: Distribution of Power

5.7: Suggestions

6: MINING AND PROCESSING OF REGOLITH

6.1: Autonomous Mining Vehicle

6.2: Transporting and Processing Regolith

6.3: Profitability of Mined Regolith

7 CONCLUSIONS

References

Additional Sources

Table of Figures

Figure 1: Deuterium-Tritium Fusion Reaction (Van Eester, 2008)

Figure 2: Ilmenite Reduction (Knudsen, 1992)

Figure 3: Magma Electrolysis (Keller, 2002)

Figure 4: Lunar Telescope (Harris 2008)

Figure 5: Primary Functions and Support Functions

Figure 6: Functional Requirements Timeline

Figure 7: Considered Base Designs

Figure 8:Module (1), Airlock Connector (2), atop Regolith (3)……………………………….…….42

Figure 9: Individual habitat module design

Figure 10: Stress levels in pressurized vessels with domed top and flat top.

Figure 11: Airlock Connector design

Figure 12: Final Layout

Figure 13: Modules shielded with regolith

Figure 14: Nuclear Reactor (Eckart, 1996, pg. 67)

Figure 15: Regolith moving robot (Sadeh, 1992, pg 1075).

Figure 16: Breakdown of the elements contained in regolith. .

Figure 17: Rough layout of the production/processing plant

Table of Tables

Table 1: Area Requirements in square meters for Phases 1-6

Table 2: Power Requirements in kW for Phases 1-6

Table 3: Comparison of Various Design Layouts and Construction Techniques

Table 4: Solar Cells (Eckart, 1996, pg. 61).

Table 5: Solar Dynamic Cycle (Eckart, 1996, pg. 64).

Table 6: Battery Properties (Eckart, 1996, pg. 72).

Table 7: RFC Propertes (Eckart, 1996, pg. 74)

1:INTRODUCTION

One of the National Aeronautics and Space Administration (NASA)’s goals for this century is to visit Mars, in much the same way that they did in the 60’s on the moon. As a stepping stone for this, NASA aims to build a semi-self sufficient lunar base. This involves sending a reusable lunar spacecraft to the moon with a small crew in six month shifts. The base itself would be small and prefabricated, not largely relying on the moon as a resource. The goal of NASA’s First Lunar Outpost (FLO) is to simply survive on the moon (Lindroos, 2007). This plan is a short-sighted result of NASA’s budget cuts and resulting conservatism. They refuse to commit to the moon as a permanent base because they believe that only a temporary base is necessary in the development of a Martian base. A six month venture of this type would be costly and would not yield much in the way of resources or scientific development.

A more permanent lunar base that contrasts with NASA’s smaller and less useful concept, while more expensive at the outset, would be far more beneficial for humanity. NASA does not have clear goals for the base, as it is does not want to commit to the moon. However, if a substantial, permanent base is designed and built with clear and tangible goals, that has the ability to return the initial investment, the case for colonizing the moon becomes much more convincing. A permanent lunar base would have great benefit for humanity not only in scientific progress, but it could become both functionally and economically self-sufficient.

This project will show that such a base is a realistic possibility. The economical case for the colony will be made. It will be shown that a forty year, six phase program can be implemented that will allow for the base to house forty-eight inhabitants. The base will consist of living quarters, an agricultural facility, a mining facility, a production plant, a solar power array, a nuclear power plant, and a logistical network. These different structures will be constructed as needed as the base’s development progresses. The living quarters, the power facilities, and the mining and production facilities will be discussed in some detail.

1.1: Exploitation of Lunar Resources

There are several options for making a lunar base economically self-sufficient. Helium-3 is a tremendously valuable resource for nuclear fusion research that is available in abundant quantities on the moon (Schmitt, 2008, pg. 2). Additionally, oxygen mined on the moon can be used to create tremendous amounts of rocket fuel for use in lunar missions or for sale (Sadeh, 1992, pg. 752). The moon also has a very large potential as a scientific research and advancement location. Finally, when the base is well established and entirely self-sufficient, tourism could be another source of revenue.

While devices powered by nuclear fission reactions are well-proven, more efficient and more powerful fusion reactors are not, due in large part to the lack of available Helium-3 (Santarius, 2006, pg. 3) for use in their development and operation. In the past, fusion reactor technology involved using a hydrogen fusion reaction to generate energy, with little or no success. As shown in Figure 1, fusion technology currently uses deuterium (hydrogen-2), a hydrogen isotope, in a reaction with tritium (hydrogen-3), to release a great deal of energy, and create a neutron and helium-4 atom. However, as there are currently no materials capable of withstanding the temperatures required to contain a fusion reaction, electromagnetic forces must be used.

Unfortunately, electromagnetic containment technology is not presently capable of practically containing the reaction for long periods of time. It is believed that using helium-3 in place of tritium will result in a reaction that can be contained with electrostatic forces, which are much less complex and more reliable than the electromagnetic forces required for a deuterium-tritium reaction (Schmitt, 2008, pg. 3).

Research shows that the fusion process has the potential to be a very efficient form of power generation if the technology is perfected. Very little of the reactant will be needed in order for the process to continue to produce power. For example, only 220 pounds of helium-3 would be required to power a city the size of Detroit for an entire year (Schmitt, 2008, pg. 4). Unfortunately, even this small amount of helium-3 is extremely difficult to obtain on earth.

However, there is evidence that the moon is rich in Helium-3, especially at the equatorial regions (Mendell, 1985, pg. 439). Undisturbed areas of regolith could contain between twenty and thirty parts per billion of helium-3 by weight. While this may seem insignificant, it is indeed a large enough concentration to make mining the moon for this resource economically viable. The amount of helium-3 available on the moon is approximately 2 million times as much as is available on earth (Elowitz, 2008). However, despite its relative abundance, it must still be mined and processed. As this is a large operation that requires a tremendous amount of power and manual labor, it will be performed almost entirely by robots. An area of ¾ of a square mile, mined nine feet deep, could yield approximately 220 pounds of helium-3 (Schmitt, 2008, pg. 4).

While helium-3 will be useful for power generation on the moon once fusion reactors are perfected, it is present in such quantities on the moon that it could be extremely valuable for nuclear fusion reactors on earth. It is estimated that the 220 pounds mined from the ¾ square mile area would be worth approximately 141 million dollars if a fusion reactor is perfected. This necessitates making mining and retrieval of helium-3 a major objective early in the lunar base endeavor so that nuclear fusion can become a reality in time for use on the base and for sale to support the base.

The moon is extremely rich in oxygen in the form of oxides present in the regolith and rocks that covers the lunar surface. In fact, lunar soil and rocks are about 45% oxygen, and the metals to which it is bonded could be extracted, with varying degrees of difficulty, as a usable resource (Eckart, 2006). Thus the lunar soil will provide an enormous amount of oxygen that is more than sufficient for supporting the life systems of a lunar base. The rest of the available oxygen could be used for the production of rocket fuel, both for use on the lunar base and for sale to support the lunar base financially.

There are several options available for extracting oxygen from the regolith and rocks on the moon’s surface. The most straight-forward and likely category of oxygen extraction is called ilmenite reduction, as can be seen in Figure 2. This involved mixing ilmenite (iron titanium oxide, FeTiO3) with a reducing agent (such as hydrogen), resulting in the production of iron, titanium dioxide, and water. The water can then be reduced to hydrogen and oxygen. This is only one type of ilmenite reduction, and a different reducing agent would produce different products. This method would probably become widely used if large quantities of hydrogen became available from low earth orbit, which seems likely (Sadeh, 1992, pg. 754).

Another process for obtaining oxygen on the lunar surface is magma electrolysis, which is shown in Figure 3. This process involves using large amounts of energy to melt lunar rocks to magma, and then electrolyzing the resulting magma to split it into oxygen, various metals, and silicate slag (Sadeh 1992 pg. 739). Electrolysis itself is the process by which an electric current is passed through a compound, separating it into its constituent elements or simpler compounds. While this process requires a very large amount of energy, it does not require a reactant, and thus, would require fewer supplies from earth.

A newer, more experimental form of oxygen extraction involves simply covering a section of regolith and superheating it to the point where gases simply escape from the metals to which they are bonded. They are then collected, separated, and stored. Like magma electrolysis, this does not require a reactant from earth, and like ilmenite reduction, does not require excessive amounts of energy. It is also comparatively simple, and can be performed rather quickly (Kokh, 1998). However, it is not as well-proven or sound as the more traditional methods of ilmenite reduction and magma electrolysis. Additionally, during the heating of the regolith, it is very important that the regolith not be disturbed, or the gases will escape. This makes the process more difficult and time consuming.

With the oxygen mined, some of it can be used for the obvious respiration needs of life on the base. Still more can be used as an oxidizer for fuel for earth-to-moon spacecraft propulsion. However, most of it can be sold back to other space programs on earth as a crucial ingredient in spacecraft fuel. The other ingredient will most likely be the hydrogen collected from low earth orbit (Wilkes, 2007, pg. 1) though this second ingredient could be any number of other things, including by-products of magma electrolysis or ilmenite reduction. The most likely scenario involves this mined oxygen being combined with hydrogen from low earth orbit and turned into rocket fuel on the lunar base itself, for later use or sale as a spacecraft propellant.

1.2: Science

While the moon holds great promise as a resource exploitation platform, it also has a tremendous amount of potential for scientific research. The lower gravitational field and lack of atmosphere on the moon makes it possible to conduct scientific experiments that would be extremely difficult or impossible on earth. Large, high energy particle accelerators could be built more easily on the moon because of the vacuum. Intersecting Storage Ring (ISR) accelerators require a vacuum, such as the one available on the moon, to operate effectively (Landis, 1990).

The lack of atmosphere and the one sixth gravity of the moon makes launching large vehicles and structures much easier and more affordable than on the earth. A space-station could be sent from the moon to low earth orbit that is much larger than would be possible from the earth’s surface. Missions to other parts of the solar system or beyond would also be much less expensive and difficult from a lunar base than from earth (Eckart, 2006).

The clear sky, lack of atmosphere, and the steady ground available on the far side of the moon would allow for a very large and powerful telescope to be built similar to the one shown in Figure 4.

A telescope built here would not be affected by the atmosphere and would yield images of far more clarity than anything available at this point, including the Hubble space telescope. Such a telescope could be built without the compromises associated with an earth-based or satellite-type telescope: it could be large, have no atmosphere or interference, and would not have to be self-powered (Elowitz, 2008). The images obtained could enhance mankind’s understanding of the solar system and the origins of the universe. Just as the earth has served as an observatory platform for the moon, a lunar base would allow for extensive observation of the earth. An entire hemisphere of the earth would be visible, as well as both poles (Elowitz, 2008). This would be important for studying weather patterns on a global scale, an important capability in the context of global warming.

It has been theorized that the moon was originally part or all of the earth’s mantle, and was broken away by a collision with a very large meteorite or small planet. Research from a scientific facility on the moon would allow for analysis for the composition of the moon, and could lead to great discoveries concerning the formation of the moon and earth. Because the moon is currently not disturbed by atmospheric conditions or habitation, it serves as a perfect record of the solar system and its history. By studying the lunar surface and impact sites, there could be large advancements made in mankind’s understanding of the solar system (Eckart, 2006).

1.3: Tourism

When the lunar base is well-established and self-sufficient both functionally and economically, it can become profitable. At this point, the base will be secure enough to afford leisure time and attractions, and a lunar hotel can be built. People will pay simply to visit the lunar base, and the era of space tourism can begin. The lower gravity will allow for things not yet experienced on earth, and as long as the tourists do not stay long enough for the lower gravity to cause muscle atrophy, there should be no adverse health effects (Smith, 2007).

2: OVERVIEW OF THE DEVELOPMENT OF A LUNAR BASE

The proposal for a sustainable lunar base is comprised of six phases that will last approximately forty years. This program will cover everything from the first delivery and robotic assembly of initial structures to the point at which the base is fully self-sufficient and ready for free expansion. Phase 1I involves the initial payloads sent to the moon along with the robots and autonomous vehicles that will lay out the first structures to be built and assembled. The use of autonomous vehicles is important because of dangerous lunar radiation: the delivery and assembly of structures and equipment will occur before proper shielding can be implemented, so it can not safely be performed by humans. This phase will cover the first five years. Phase 2II involves robots digging the trenches and gathering regolith with which to cover the living quarters. The first stage of crew arrivals, with assistance from robots and tools, will assemble the prefabricated living quarters and bury them under regolith so as to provide protection against harmful radiation and meteorites. The solar power grid will also need to be assembled to provide power for the living quarters. The nuclear power plant will not be needed yet , sinceas the mining facility is what will needwill require the majority of the power requirements of produced on the base as a whole. This phase will require ten years for completion. Phase III 3 will have encompass much of the construction of the agricultural, mining and processing, and research facilities. The nuclear power plant will need to be integrated into the base so as to provide the massive amount of power needed by the mining and processing facilities. Also, the expansion of the crew will be necessary to provide the additional manpower needed to sustain the multiple stages of the base being introduced in this phase. A network of roads will need to be constructed in Phase III 3 to accommodate the movement of regolith between the mining and production facilities. Regolith will provide raw materials needed to further expand the base, oxygen and hydrogen to sustain the base, and Helium-3 to send back to earth. Another ten years will be required for this phase, bringing the total time invested to 25 years. Phases VI4, V5, and VI 6 involve the use of local lunar materials to expand the base, accommodating further crews of astronauts to inhabit the base, and building more living spaces using raw lunar materials. The use of such local resources is vital since sending these materials from earth is extremely costly. Also, a trade network will be setup in these stages between earth and the Moon. Helium-3, Oxygen, and Hydrogen will be sent from the Moon to earth in exchange for essential supplies, such as food, medicine, nuclear fuel, and other necessities. Phases 4, 5, and 6 will each require five years, as shown in Figure 6.